Blacklisting/Fully paid holiday now being unpaid

Possible blacklisting for an outstanding amount on a previous holiday which was paid in full .have the deposit records and proof of payment also had to pay an excess amount for levies on arrival which was not mentioned nor included in the total paid Now been contacted by the establishment owner to pay my outstanding balance almost 800 which wasn't paid to the establishment and I will risk blacklisting if not paid up

Unable to make contact with safari since and are frustrated with the situation as they emailed me also mention of short pay when the total quotation and total paid are correct excluding what was paid cash on arrival .